Iron is the world's leading nutrient deficiency and a has been a hot topic of medicine and supplementation for decades. Iron intake varies widely across the world and many factors play a role in how well it is absorbed and utilized by the body. Excessive iron in the blood in the form of hemochromatosis can lead to disastrous health consequences as well. There are literally thousands of different iron supplements out there and plenty of arguments over which one is the best to take for anemia. Doctors also typically prescribe iron pills for anemia and iron deficiency in extraordinarily high amounts. Balancing iron levels is tricky because both low iron and high iron can be damaging to health. Supplements should never be used unless there is a diagnosed deficiency because excessive iron intake may raise the risk of cancer and heart disease.


  • Carries oxygen within hemoglobin in red blood cells
  • Involved in amino acid metabolism
  • Essential for collagen production
  • Required in carnitine synthesis and use
  • Used in thyroid hormone synthesis

Primary deficiency symptoms and diseases

  • Iron deficiency anemia
  • Fatigue
  • Weakness
  • Dizziness or lightheadedness
  • Cold hands and feet
  • Pale skin
  • Poor exercise performance

Food Sources

This may start a debate between the plant based and omnivorous crowds, but plant and animal sources of iron differ in their absorption rates and utilization quite substantially. Heme iron is found in animal products like meat and is typically very easily absorbed and used by the body, but also is more difficult to remove in excess. Non-heme iron is found in plants and has poor absorption. Nutrient inhibitors like phytate, oxalic acid, tannins, and others can limit the absorption of iron from food, which can either be a good or bad thing depending on your personal iron status. Most grains, beans, nuts and seeds contain iron, but have limited absorption due to nutrient inhibitors. Tannins from tea and coffee also limit absorption, as do dairy products. Vitamin C boosts absorption of iron significantly.

The RDA (recommended daily allowance) for iron is 18 mg for women, and 8 mg for men.

  • Organ meat
  • Meats and seafood
  • Molasses
  • Beans and legumes
  • Nuts and seeds
  • Green leafy vegetables
  • Whole grains
  • Refined and fortified grains


We must reiterate that supplements should never be used unless there is a diagnosed deficiency, and even then, blood iron levels need to be monitored closely when supplementing to avoid going too high. Many elemental forms of iron are very poorly absorbed and can cause side effects like nausea, vomiting, and constipation. Food based iron supplements would be preferable if a higher iron content is needed due to their low side effect profile. Look for supplements that contain vitamin C to ensure adequate absorption, along with B12 and B6 as cofactors for blood cell formation.

*Note:* Iron overdose from supplements is one of the leading causes of poisoning in children and iron supplements should always be kept out of the reach of children.

  • Liver tablets - preferable because of the high absorption
  • Plant based iron - second to liver tablets for food based iron
  • Ferric sulfate
  • Ferrous gluconate
  • Ferrous fumarate
  • Ferrous ascorbate

Who needs it most?

Also worth mentioning here is that men require much less iron and many doctors are advising now that men regularly check their iron levels and donate blood to relieve themselves of excess iron.

  • Premenopausal women
  • Trauma victims
  • Those with GI bleeding disorders

Other tips

  • Food works best and has little to no side effects
  • Organ meats or liver supplements have great amounts of iron that is easily accessible to the body
  • If lower iron is the goal, it is quite easy to reduce absorption by consuming things like coffee and tea simultaneously